Renal function and proteinuria after successful immunosuppressive therapies in patients with FSGS

Focal Segmental Glomerulosclerosis: Assessing the Risk of Relapse

Introduction

Kidney outcomes are improved in primary focal segmental glomerulosclerosis (FSGS) by maintaining a remission in proteinuria. However, characteristics associated with relapses are uncertain. We sought to identify these by analyzing each remission.

Methods

We performed a retrospective study in patients with biopsy-proven lesions of FSGS, absent identifiable secondary cause, who had at least 1 remission from nephrotic-range proteinuria. In each patient, we identified every remission, every relapse, and their durations. Using a multilevel logistic regression to account for the clustering of multiple remissions within a patient, we tested which clinical characteristics were independently associated with relapses.

Results

In 203 individuals, 312 remissions occurred, 177 with and 135 without relapse. A minority of remissions were atypical, defined by either absent hypoalbuminemia and/or no immunosuppression (IS), in contrast to the classic nephrotic syndrome that remits with IS. Atypical remission variants were just as likely to relapse as the classical presentation. Only 24% of remission events were on maintenance therapy at relapse. Independent characteristics associated with relapses were higher maximal proteinuria while nephrotic; and in remission, higher nadir proteinuria, lower serum albumin, and higher blood pressure. Using these variables, we created a tool estimating the 1-year risk of relapse ranging from 9% to 80%, well-calibrated to the observed data.

Conclusion

In FSGS, relapses are frequent but predictable using independent clinical characteristics. We also provide evidence that atypical presentations remit and relapse following the same pattern as classic FSGS presentations. Treatment strategies to prolong remission duration should be addressed in future trials.

Efficacy and Safety of Immunosuppressive Therapy in Primary Focal Segmental Glomerulosclerosis: A Systematic Review and Meta-analysis

Rationale & Objective

Focal segmental glomerulosclerosis (FSGS) is a rare condition that can lead to kidney function decline and chronic kidney failure. Immunosuppressants are used to treat primary FSGS. However, their efficacy and safety in FSGS are not clearly established. We assessed current knowledge on clinical effectiveness and safety of immunosuppressants for primary FSGS.

Study Design

Systematic review of randomized controlled trials, interventional nonrandomized controlled trials, observational studies, retrospective studies, and registries.

Setting & Participants

Patients with primary and genetic FSGS.

Selection Criteria for Studies

Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for English-language, primary-FSGS studies from inception to 2019. Clinical outcomes were changes from baseline in proteinuria, kidney function, and kidney survival.

Data Extraction

2 investigators independently screened studies and extracted data.

Analytical Approach

Study results were summarized using random-effects models either as ratios of means between follow-up and baseline measurements or as HRs.

Results

We included 98 articles. Substantial heterogeneity was observed in patient baseline characteristics and study designs. Most studies assessed treatment with corticosteroids alone or combined with other drugs, mainly immunosuppressants. Patients treated with immunosuppressants showed reduced proteinuria (14 studies; ratio of means, 0.36; 95% CI, 0.20-0.47), decreased creatinine clearance (mean difference, −25.03; 95% CI, −59.33 to −9.27) and (significantly) lower estimated glomerular filtration rates (mean difference, −7.61 mL/min/1.73 m²; 95% CI, −14.98 to 0.25 mL/min/1.73 m²). Immunosuppressant therapy had an uncertain effect on reducing the chronic kidney failure risk. Hypertension and infections were the most commonly reported adverse events.

Limitations

Heterogeneity in study designs, patient populations, and treatment regimens; no access to individual patient–level data.

Conclusions

This systematic review supports proteinuria reduction with immunosuppressant therapy in primary FSGS over varying follow-up periods. The effects of immunosuppressants on kidney survival remain uncertain. This review underscores the need for better-designed and adequately controlled studies to assess immunosuppressant therapy in patients with primary FSGS.

Efficacy and Safety of ACE Inhibitor and Angiotensin Receptor Blocker Therapies in Primary Focal Segmental Glomerulosclerosis Treatment: A Systematic Review and Meta-analysis

Rationale and Objective

Angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy (renin-angiotensin-aldosterone system [RAAS] inhibitor) to control proteinuria in primary and genetic focal segmental glomerulosclerosis (FSGS) follows guidelines based on other proteinuria-related kidney diseases. There is no consensus on the efficacy and safety of RAAS inhibitor therapies in primary and genetic FSGS. This systematic review assessed the effects of RAAS inhibitor therapy on kidney outcomes in these patients.

Study Design

Systematic review of randomized controlled trials, interventional nonrandomized studies, observational studies, and retrospective studies.

Setting & Study Populations

Patients with primary and genetic FSGS.

Selection Criteria for Studies

PubMed, Cochrane Library, and Embase.

Data Extraction

2 investigators independently screened studies and extracted data.

Analytical Approach

Results were summarized as the ratio of means (ROM) between baseline and follow-up measurements or as the hazard ratio using random-effects models.

Results

30 publications were selected; 5 were controlled trials (4 randomized controlled trials). 8 assessed RAAS inhibitor monotherapy, while the rest studied RAAS inhibitors in combination with other drugs, mainly immunosuppressants. On average, a 32% proteinuria reduction (ROM, 0.68; 95% CI, 0.47-0.98) and no change in creatinine clearance (ROM, 0.95; 95% CI, 0.77-1.16) from baseline to the last reported follow-up was observed in patients treated with RAAS inhibitor monotherapy. When a RAAS inhibitor was combined with other drugs, a 72% proteinuria reduction was observed from baseline to the last reported follow-up (ROM, 0.24; 95% CI, 0.08-0.75). The published data did not allow for the assessment of the effects of RAAS inhibitor monotherapy on estimated glomerular filtration rate and end-stage kidney disease risks.

Limitations

Large study heterogeneity in design, patient populations, and treatment regimens. No access to individual patient-level data.

Conclusions

This review supports the tendency to observe a proteinuria reduction with RAAS inhibitors in patients with primary FSGS. RAAS inhibitor monotherapy was associated with maintained kidney function, as shown by no change in creatinine clearance. Strong evidence to quantify the effects of RAAS inhibitor monotherapy on end-stage kidney disease and glomerular filtration rate was lacking. Larger, well-designed clinical trials are needed to better understand the effects of RAAS inhibitors on primary FSGS.

Interventions for focal segmental glomerulosclerosis in adults

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) can be separated into primary, genetic or secondary causes. Primary disease results in nephrotic syndrome while genetic and secondary forms may be associated with asymptomatic proteinuria or with nephrotic syndrome. Overall only about 20% of patients with FSGS experience a partial or complete remission of nephrotic syndrome with treatment. FSGS progresses to kidney failure in about half of the cases. This is an update of a review first published in 2008.

OBJECTIVES

To assess the benefits and harms of immunosuppressive and non-immunosuppressive treatment regimens in adults with FSGS.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies to 21 June 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any intervention for FSGS in adults were included. Studies comparing different types, routes, frequencies, and duration of immunosuppressive agents and non-immunosuppressive agents were assessed.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model and results were expressed as a risk ratio (RR) for dichotomous outcomes, or mean difference (MD) for continuous data with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Fifteen studies (560 participants) were included. No studies specifically evaluating corticosteroids compared with placebo or supportive therapy were identified. Studies evaluated participants with steroid-resistant FSGS. Five studies (240 participants) compared cyclosporin with or without prednisone with different comparators (no specific treatment, prednisone, methylprednisolone, mycophenolate mofetil (MMF), dexamethasone). Three small studies compared monoclonal antibodies (adalimumab, fresolimumab) with other agents or placebo. Six single small studies compared rituximab with tacrolimus, cyclosporin plus valsartan with cyclosporin alone, MMF with prednisone, chlorambucil plus methylprednisolone and prednisone with no specific treatment, different regimens of dexamethasone and CCX140-B (an antagonist of the chemokine receptor CCR2) with placebo. The final study (109 participants) compared sparsentan, a dual inhibitor of endothelin Type A receptor and of the angiotensin II Type 1 receptor, with irbesartan. In the risk of bias assessment, seven and five studies were at low risk of bias for sequence generation and allocation concealment, respectively. Four studies were at low risk of performance bias and 14 studies were at low risk of detection bias. Thirteen, six and five studies were at low risk of attrition bias, reporting bias and other bias, respectively. Of five studies evaluating cyclosporin, four could be included in our meta-analyses (231 participants). Cyclosporin with or without prednisone compared with different comparators may increase the likelihood of complete remission (RR 2.31, 95% CI 1.13 to 4.73; I² = 1%; low certainty evidence) and of complete or partial remission (RR 1.64, 95% CI 1.10 to 2.44; I² = 19%) but not of partial remission (RR 1.36, 95% CI 0.78 to 2.39, I² = 22%). In Individual studies, cyclosporin with prednisone versus prednisone may increase the likelihood of partial (49 participants: RR 7.96, 95% CI 1.09 to 58.15) or complete or partial remission (49 participants: RR 8.85, 95% CI 1.22 to 63.92) but not of complete remission. The remaining individual comparisons may make little or no difference to the likelihood of complete remission, partial remission or complete or partial remission compared with no treatment, methylprednisolone, MMF, or dexamethasone. Individual study data and combined data showed that cyclosporin may make little or no difference to the outcomes of chronic kidney disease or kidney failure. It is uncertain whether cyclosporin compared with these comparators in individual or combined analyses makes any difference to the outcomes of hypertension or infection. MMF compared with prednisone may make little or no difference to the likelihood of complete remission (33 participants: RR 1.05, 95% CI 0.58 to 1.88; low certainty evidence), partial remission, complete or partial remission, glomerular filtration rate, or infection. It is uncertain whether other interventions make any difference to outcomes as the certainty of the evidence is very low. It is uncertain whether sparsentan reduces proteinuria to a greater extent than irbesartan.

AUTHORS' CONCLUSIONS

No RCTs, which evaluated corticosteroids, were identified although the KDIGO guidelines recommend corticosteroids as the first treatment for adults with FSGS. The studies identified included participants with steroid-resistant FSGS. Treatment with cyclosporin for at least six months was more likely to achieve complete remission of proteinuria compared with other treatments but there was considerable imprecision due to few studies and small participant numbers. In future studies of existing or new interventions, the investigators must clearly define the populations included in the study to provide appropriate recommendations for patients with primary, genetic or secondary FSGS.

Steroid resistant focal segmental glomerulosclerosis: effect of arterial hyalinosis on outcome: single center study

Background. Few data with adequate evidence exists as regards the effect of Cyclosporine (CsA) and mycophenolate mofetil (MMF) on pathological prognostic parameters in patients with steroid resistant focal segmental glomerulosclerosis (FSGS). The purpose of the present study is to compare the effect of cyclosporin and mycophenolate mofetil in addition to steroids on functional and histopathologic renal parameters in patients with steroid resistant FSGS one year after treatment.Material and methods. Thirty-seven adults with primary FSGS patients resistant to steroid therapy consecutively randomized to treatment with either MMF or cyclosporine. Low dose prednisolone added to both groups. Glomerular filtration rate (GFR) and blood pressure (BP) were determined at all examinations and a second renal biopsy was taken 12 months after treatment with either of cyclosporin and mycophenolate mofetil.Results. GFR significantly increased in MMF group p < 0.01 after 6 months and unchanged after 12 months. On the other hand, GFR significantly decrease in CsA group p < 0.001 after 6 months and reduced more after 12 months p < 0.001 compared to base line levels. There was a significant difference of GFR between the 2 groups at 6 months p < 0.001. The extent of proteinuria decreased significantly in CsA group after 12 months p < 0.001. The extent of arteriolar hyalinosis increased significantly in CsA group (0.78 to 1.81 score, p < 0.001) but was unchanged in MMF group (0.93 to 0.96 score), whereas interstitial fibrosis increased to same level in both groups (grade 3).Conclusion. Conversion to MMF in those patients may be superior to CsA as regards GFR after 12 months after treatment in spite of the presence of greater level of protein excretion. The increased arteriolar hyalinosis during CsA treatment most likely results in higher BP compared to MMF treatment in patients with FSGS resistant to steroids.

Study Design of the Phase 3 Sparsentan Versus Irbesartan (DUPLEX) Study in Patients With Focal Segmental Glomerulosclerosis

Introduction

Focal segmental glomerulosclerosis (FSGS), a histologic lesion in the kidney caused by varied pathophysiological processes, leads to end-stage kidney disease in a large proportion of patients. Sparsentan is a first-in-class orally active compound combining endothelin type A (ET_A) receptor blockade with angiotensin II type 1 (AT₁) receptor antagonism in a single molecule. A Randomized, Multicenter, Double-Blind, Parallel, Active-Control Study of the Effects of Sparsentan, a Dual Endothelin Receptor and Angiotensin Receptor Blocker, on Renal Outcomes in Patients With Primary FSGS (DUPLEX) study evaluates the long-term antiproteinuric efficacy, nephroprotective potential, and safety profile of sparsentan compared with an AT₁ receptor blocker alone in patients with FSGS.

Methods

DUPLEX is a multicenter, international, phase 3, randomized, double-blind, active-controlled study of sparsentan in patients with FSGS. Approximately 300 patients aged 8 to 75 years, inclusive (United States), and 18 to 75 years, inclusive (outside United States) will be randomized 1:1 to daily treatment with sparsentan or irbesartan. After renin-angiotensin-aldosterone system inhibitor washout, treatment will be administered for 108 weeks, with the final assessment at week 112, four weeks after withdrawal of study drug.

Results

The primary endpoint will be the slope of estimated glomerular filtration rate from week 6 to week 108. A novel surrogate efficacy endpoint, the proportion of patients achieving urinary protein-to-creatinine (UP/C) ratio of ≤1.5 g/g and >40% reduction from baseline in UP/C (FSGS partial remission endpoint: FPRE), will be evaluated at a planned interim analysis at week 36. Safety and tolerability of sparsentan will also be assessed.

Conclusion

The phase 3 DUPLEX study will characterize the long-term antiproteinuric efficacy and nephroprotective potential of dual ET_A and AT₁ receptor blockade with sparsentan in patients with FSGS.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond to corticosteroids in the first episode of nephrotic syndrome (initial resistance) or develop resistance after one or more responses to corticosteroids (delayed resistance) may be treated with immunosuppressive agents including calcineurin inhibitors (CNI) (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). However, response to these agents is limited so newer agents are being assessed for efficacy. This is an update of a review first published in 2004 and updated in 2006, 2010 and 2016.

OBJECTIVES

To evaluate the benefits and harms of different interventions used in children with idiopathic nephrotic syndrome, who do not achieve remission following four weeks or more of daily corticosteroid therapy.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies to 17 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with steroid-resistant nephrotic syndrome (SRNS). Studies, which enrolled children and adults but in which paediatric data could not be separated from adult data, were also included.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed risk of bias and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). For continuous outcomes, results were expressed as mean difference (MD) and 95% CI. Data were pooled using the random effects model. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Twenty-five studies (1063 participants) were included. Fourteen studies were at low risk of bias for sequence generation and allocation concealment. Five and 19 studies were at low risk of performance and detection bias. Fourteen, 14 and 13 studies were at low risk of attrition bias, reporting bias and other bias respectively. Cyclosporin compared with placebo or no treatment may increase the number of participants who achieve complete remission (4 studies, 74 participants: RR 3.50, 95% CI 1.09 to 11.20) or complete or partial remission (4 studies, 74 children: RR 3.15, 95% CI 1.04 to 9.57) by 6 months (low certainty evidence). It is uncertain whether cyclosporin increases the likelihood of worsening hypertension or reduces the likelihood of end-stage kidney disease (very low certainty evidence). CNI compared with IV cyclophosphamide (CPA) may increase the number of participants with complete or partial remission at 3 to 6 months (2 studies, 156 children: RR 1.98, 95% CI 1.25 to 3.13) (low certainty evidence) and probably reduces the number with treatment failure (non response, serious infection, persistently elevated creatinine (1 study, 124 participants: RR 0.32, 95% CI 0.18 to 0.58) (moderate certainty evidence) with little or no increase in serious infections (1 study, 131 participants: RR 0.49, 95% CI 0.16 to 1.56) (moderate certainty evidence). Tacrolimus compared with cyclosporin may make little or no difference to the number who achieve complete or partial remission (2 studies, 58 participants: RR 1.05, 95% CI 0.87 to 1.25) (low certainty evidence) or in the number with worsening hypertension (2 studies, 58 participants: RR 0.41, 95% CI 0.08 to 2.15) (low certainty evidence). Cyclosporin compared with mycophenolate mofetil (MMF) and dexamethasone probably makes little or no difference to the number who achieve complete or partial remission (1 study, 138 participants: RR 2.14, 95% CI 0.87 to 5.24) (moderate certainty evidence) and makes little or no difference to the number dying (1 study, 138 participants: RR 2.14, 95% CI 0.87 to 5.24) or with 50% reduction in glomerular filtration rate (GFR) (1 study, 138 participants: RR 2.29, 95% CI 0.46 to 11.41) (low certainty evidence). Among children, who have achieved complete remission, tacrolimus compared with MMF may increase the number of children who maintain complete or partial response for 12 months (1 study, 60 children: RR 2.01, 95% CI 1.32 to 3.07) (low certainty evidence). Oral CPA with prednisone compared with prednisone alone may make little or no difference to the number who achieve complete remission (2 studies, 84 children: RR 1.06, 95% CI 0.61 to 1.87) (low certainty evidence). IV CPA compared with oral CPA (2 studies, 61 children: RR 1.58, 95% CI 0.65 to 3.85) and IV compared with oral CPA plus IV dexamethasone (1 study, 49 children: RR 1.13, 95% CI 0.65 to 1.96) may make little or no difference to the number who achieve complete remission (low certainty evidence). It is uncertain whether rituximab and cyclosporin compared with cyclosporin increases the likelihood of remission because the certainty of the evidence is very low. It is uncertain whether adalimumab or galactose compared with conservative therapy increases the likelihood of remission because the certainty of the evidence is very low. Two studies reported that ACEi may reduce proteinuria in children with SRNS. One study reported that the dual angiotensin II and endothelin Type A receptor antagonist, sparsentan, may reduce proteinuria more effectively than the angiotensin receptor blocker, irbesartan.

AUTHORS' CONCLUSIONS

To date RCTs have demonstrated that CNIs may increase the likelihood of complete or partial remission compared with placebo/no treatment or CPA. For other regimens assessed, it remains uncertain whether the interventions alter outcomes because the certainty of the evidence is low. Further adequately powered, well designed RCTs are needed to evaluate other regimens for children with idiopathic SRNS. Since SRNS represents a spectrum of diseases, future studies should enrol children from better defined groups of patients with SRNS.

Hypertension in Childhood Nephrotic Syndrome

Arterial hypertension (HTN) is commonly encountered by clinicians treating children with steroid sensitive (SSNS) and steroid resistant nephrotic syndrome (SRNS). Although the prevalence of HTN in SSNS is less documented than in SRNS, recent studies reported high prevalence in both. Studies have estimated the prevalence of HTN in different patient populations with NS to range from 8 to 59.1%. Ambulatory HTN, abnormalities in BP circadian rhythm, and measures of BP variability are prevalent in patients with NS. Multiple mechanisms and co-morbidities contribute to the pathophysiology of HTN in children with NS. Some contributing factors are known to cause acute and episodic elevations in blood pressure such as fluid shifts, sodium retention, and medication side effects (steroids, CNIs). Others are associated with chronic and more sustained HTN such as renal fibrosis, decreased GFR, and progression of chronic kidney disease. Children with NS are more likely to suffer from other cardiovascular disease risk factors, such as obesity, increased measures of arterial stiffness [increased carotid intima-media thickness (cIMT), endothelial dysfunction, increased pulse wave velocity (PWV)], impaired glucose metabolism, dyslipidemia, left ventricular hypertrophy (LVH), left ventricular dysfunction, and atherosclerosis. Those risk factors have been associated with premature death in adults. In this review on HTN in patients with NS, we will discuss the epidemiology and pathophysiology of hypertension in patients with NS, as well as management aspects of HTN in children with NS.

T-lymphocyte-expressing inflammatory cytokines underlie persistence of proteinuria in children with idiopathic nephrotic syndrome

OBJECTIVE

There is evidence of an important role of immune system changes in the triggering and maintenance of idiopathic nephrotic syndrome (INS). The aim of this study was to investigate the expression of cytokines in lymphocyte populations of patients with INS in comparison to healthy individuals, according to proteinuria.

METHODS

This cross-sectional study included 44 patients with INS and eight healthy children, matched for age and sex (controls). Patients were subdivided according to proteinuria: persistent proteinuria or partial remission (PP≥300mg/24h, n=17) and low proteinuria or complete remission (LP<300mg/24h, n=27). Ex vivo analysis of peripheral blood leukocytes by flow cytometry was performed using surface markers for T-lymphocytes, TCD4, TCD8, natural killer (NK) cells, NKT, and B-lymphocytes. Frequencies of intracellular cytokines were analyzed in these cells.

RESULTS

The frequencies of B-lymphocytes, NK cells, and NKT cells were lower in INS than in controls, whereas INS patients had a higher frequency of CD4⁺tumor necrosis factor (TNF)-α⁺ cells than controls. Cytotoxic-T-lymphocytes expressing IFN-γ were lower in INS than in controls. Patients with PP showed higher frequencies of CD4-T-lymphocytes expressing IFN-γ and TNF-α than controls. CD8-lymphocytes expressing TNF-α were increased in PP group when compared with LP and controls, while CD8⁺interferon (IFN)-γ⁺ cells were lower than in LP and in controls.

CONCLUSION

Regardless the level of proteinuria, INS patients had increased expression of TNF-α in CD4-lymphocytes and reduced expression of IFN-γ in CD8-lymphocytes. Persistence of proteinuria was associated with higher levels of inflammatory markers.

Cyclosporine-based immunosuppressive therapy for patients with steroid-resistant focal segmental glomerulosclerosis: a meta-analysis

OBJECTIVE

Focal segmental glomerulosclerosis (FSGS) is a leading cause of end-stage kidney disease that requires immunosuppressive treatment as therapy. Few studies have been specifically designed to assess the efficacy of cyclosporine (CSA) in patients with steroid-resistant FSGS. This study investigated the efficacy of CSA-based therapy in steroid-resistant FSGS.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched through April 30, 2014 using the keywords "cyclosporine", "steroid-resistant", "focal segmental glomerulosclerosis", and "FSGS". Studies with an adult and children with steroid-resistant primary FSGS treated with CSA-based therapy with or without steroid use were included. Complete, partial, and overall remission were the primary outcomes. Change in proteinuria, serum creatinine, and estimated glomerular filtration rate (eGFR) following treatment were secondary outcomes.

RESULTS

Seven randomized controlled trials with a total of 373 patients were included. Five studies were included in the meta-analysis to assess complete, partial, and overall remission of FSGS. Compared with other treatments, CSA-based therapy resulted in a significantly greater partial remission rate (p = .018), but complete (p = .226) or overall remission rate (p = .050). CSA-based therapy also resulted in similar change in proteinuria (p = .084), serum creatinine (p = .772), and eGFR (p = .155) compared with other therapy. Study limitations included small sample size and heterogeneity in age and comparative treatments across the studies.

CONCLUSIONS

Cyclosporin-based treatments provided a significantly better partial remission rate as compared with other therapies.

Steroid-resistant nephrotic syndrome: a persistent challenge for pediatric nephrology

Steroid-resistant nephrotic syndrome remains a challenge to treat, but various efforts are underway to better understand the pathogenesis and improve patient outcomes. This review provides an update on the newer advances in understanding the molecular etiologies for a variety of podocyte abnormalities, potential circulating factors that may initiate and sustain the steroid-resistant state, genetic mutations, and precision medicine treatment modalities in this continuously perplexing disorder.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond may be treated with immunosuppressive agents including calcineurin inhibitors (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi). Optimal combinations of these agents with the least toxicity remain to be determined. This is an update of a review first published in 2004 and updated in 2006 and 2010.

OBJECTIVES

To evaluate the benefits and harms of different interventions used in children with idiopathic nephrotic syndrome, who do not achieve remission following four weeks or more of daily corticosteroid therapy.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register (up to 2 March 2016) through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

RCTs and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with SRNS.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed risk of bias and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). Data were pooled using the random effects model.

MAIN RESULTS

Nineteen RCTs (820 children enrolled; 773 evaluated) were included. Most studies were small. Eleven studies were at low risk of bias for allocation concealment and only four studies were at low risk of performance bias. Fifteen, eight and 10 studies were at low risk of detection bias, attrition bias and reporting bias respectively. Cyclosporin when compared with placebo or no treatment significantly increased the number of children who achieved complete remission. However this was based on only eight children who achieved remission with cyclosporin compared with no children who achieved remission with placebo/no treatment in three small studies (49 children: RR 7.66, 95% CI 1.06 to 55.34). Calcineurin inhibitors significantly increased the number with complete or partial remission compared with IV cyclophosphamide (2 studies, 156 children: RR 1.98, 95% CI 1.25 to 3.13; I² = 20%). There was no significant differences in the number who achieved complete remission between tacrolimus versus cyclosporin (1 study, 41 children: RR 0.86, 95% CI 0.44 to 1.66), cyclosporin versus mycophenolate mofetil plus dexamethasone (1 study, 138 children: RR 2.14, 95% CI 0.87 to 5.24), oral cyclophosphamide with prednisone versus prednisone alone (2 studies, 91 children: RR 1.06, 95% CI 0.61 to 1.87), IV versus oral cyclophosphamide (1 study, 11 children: RR 3.13, 95% CI 0.81 to 12.06), IV cyclophosphamide versus oral cyclophosphamide plus IV dexamethasone (1 study, 49 children: RR 1.13, 95% CI 0.65 to 1.96), and azathioprine with prednisone versus prednisone alone (1 study, 31 children: RR 0.94, 95% CI 0.15 to 5.84). One study found no significant differences between three agents (cyclophosphamide, mycophenolate mofetil, leflunomide) used in combination with tacrolimus and prednisone. One study found no significant difference in the percentage reduction in proteinuria (31 children: -12; 95% CI -73 to 110) between rituximab with cyclosporin/prednisolone and cyclosporin/prednisolone alone. Two studies reported ACEi significantly reduced proteinuria.

AUTHORS' CONCLUSIONS

To date RCTs have demonstrated that calcineurin inhibitors increase the likelihood of complete or partial remission compared with placebo/no treatment or cyclophosphamide. For other regimens assessed, it remains uncertain whether the interventions alter outcomes because the certainty of the evidence is low. Further adequately powered, well designed RCTs are needed to evaluate other regimens for children with idiopathic SRNS. Since SRNS represents a spectrum of diseases, future studies should enrol children from better defined groups of patients with SRNS.

Serum glomerular albumin permeability activity: association with rapid progression to end-stage renal disease in focal segmental glomerulosclerosis

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a major cause of renal failure. Sera of some FSGS patients increase glomerular albumin permeability (Palb) during in vitro testing and cause proteinuria in experimental animals.

OBJECTIVES

To determine whether permeability activity of FSGS serum (Palb activity) is associated with rate of progression to renal replacement therapy (RRT).

DESIGN

This is an observational study based on medical and demographic information and Palb activity testing.

SETTING

Studies were performed at Medical College of Wisconsin.

PATIENTS

Serum was submitted by patients' nephrologists for measurement of Palb activity. Each patient had had a biopsy diagnosis of FSGS, had reached ESRD and was on dialysis or had a functioning transplant.

MEASUREMENTS

Palb activity, clinical characteristics and time between biopsy diagnosis and RRT (T-RRT) were recorded for each patient.

METHODS

Palb activity was measured using established in vitro techniques.

RESULTS

Palb and T-RRT were inversely correlated. Neither Palb nor T-RRT varied with demographics or medications. Kaplan-Meier survival curves showed that patients with Palb ≥ 0.5 progressed to RRT more rapidly than others.

LIMITATIONS

Only patients who had reached RRT were included. Limited clinical information was available for each patient. Central verification of biopsy characteristics was not performed and detailed descriptions of renal histology were not available.

CONCLUSIONS

Palb activity is associated with the rate of progression to RRT in patients with FSGS. Additional observations will be needed to verify that Palb activity predicts prognosis and is useful in stratifying patients for clinical decision making or treatment trials.

Response to cyclosporine in steroid-resistant nephrotic syndrome: discontinuation is possible

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS) is still regarded as a serious disease although treatment with cyclosporine (CSA) has improved outcome. However, the duration of treatment in responders is unclear, and treatment of patients with genetic causes is a matter of debate.

METHODS

Thirty-six patients with SRNS were studied retrospectively. Median age at presentation was 3.2 (range, 0.06-15.0) and median follow-up 15.5 years (range, 1.8-27.7), respectively; 23 (64%) had focal segmental glomerulosclerosis (FSGS) on biopsy. In 33/36 patients (92%), genetic testing was performed for at least three most common genes known to be mutated in SRNS.

RESULTS

Nineteen patients (53%), especially those with minimal change nephrotic syndrome (MCNS) at initial biopsy (p < 0.002), entered complete remission with CSA monotherapy, including one patient with compound heterozygous NPHS1 and dominant ACTN4 mutation, respectively. Ten patients entered partial remission (28%, all FSGS), including two with NPHS2 mutations. Seven patients (six FSGS, one MCNS) did not respond to treatment. In 15 of 19 responders to CSA, treatment was stopped after a median of 3.1 years (range, 0.5-14) and no further relapses occurred in 11/15 (73%) patients with median follow-up of 9.7 years.

CONCLUSIONS

CSA monotherapy is effective in SRNS. Discontinuation of CSA is possible in many patients with complete remission.

Tacrolimus therapy in adult-onset steroid-resistant nephrotic syndrome due to a focal segmental glomerulosclerosis single-center experience

INTRODUCTION

Management of adults with steroid-resistant (SR) nephrotic syndrome due to focal segmental glomerulosclerosis (FSGS) is a challenging task. Is tacrolimus (TAC) effective in this situation without serious adverse effects? This prospective study was done to answer this question.

MATERIALS AND METHODS

In patients with SR nephrotic syndrome due to FSGS, oral TAC (0.1 mg/kg/day) was started targeting a trough level of 5-10 ng/mL along with oral prednisolone (0.15 mg/kg/day) for 48 weeks. In patients with complete remission (CR), TAC dose was reduced to a target of 3-6 ng/mL whereas in partial responders, TAC trough levels were kept at 5-10 ng/mL. TAC was discontinued in those with no remission at 24 weeks and was deemed TAC resistant. Outcome, namely CR and partial remission (PR), was assessed at the end of 24 and 48 weeks. All patients were prospectively followed for 60 weeks. Relapses after CR or PR were recorded; adverse effects, namely nephrotoxicity (>25% rise in creatinine), cosmetic effects, infections and hyperglycemia, were recorded every month.

RESULTS

A total of 44 SR-FSGS [not otherwise specified 33 (75%), tip lesion 03 (6.8%) and cellular variant 8 (18.1%)] were analyzed. Mean age was 25.16 ± 8.26 (18-51) years. Of 44 patients, CR and PR were achieved in 17 (38.6%) and 06 (13.6%) patients, respectively. TAC resistance was seen in 21 (47.7%) patients. Time taken to achieve remission was 15.2 ± 6 weeks. Five (21.7%) patients with CR had relapse on tapering the dose and seven (30.4%) after stopping TAC. Reversible nephrotoxicity was seen in seven (15.9%) and irreversible in four patients (9%). TAC-related diarrhea was the problem in 10 (22.7%), and infections were seen in 19 patients (43.1%). Impaired fasting glucose and diabetes mellitus were seen in 10 patients (22.7%).

CONCLUSION

TAC is an effective agent in the management of SR-FSGS. However, strict renal function and blood sugar monitoring is required due to its potential nephrotoxicity and diabetogenic potential.

Podocyte repopulation by renal progenitor cells following glucocorticoids treatment in experimental FSGS

Prednisone is a mainstay of treatment for patients with focal segmental glomerulosclerosis (FSGS), a disease characterized by reduced podocyte number and glomerulosclerosis. Although the systemic immune-modulatory effects of prednisone are well-known, direct tissue effects on glomerular cells are poorly understood. Experimental FSGS was induced in mice with a cytotoxic anti-podocyte antibody, resulting in an abrupt decrease in podocyte number by day 3, proteinuria, and the development of glomerulosclerosis. Administering daily prednisone to mice with FSGS, beginning at day 3, significantly increased podocyte number at weeks 2 and 4. Podocyte number did not increase in control mice with FSGS given DMSO. The increase in podocyte number in prednisone-treated mice correlated significantly with reduced glomerulosclerosis. Prednisone reduced podocyte apoptosis measured by synaptopodin⁺/caspase-3⁺ double staining. Additionally, the number of podocyte progenitors, defined as cells expressing both a parietal epithelial cell protein and a podocyte protein, was significantly increased in prednisone-treated mice with FSGS at weeks 2 and 4. This was associated with increased phospho-ERK staining in both parietal epithelial cells (PAX2⁺/p-ERK⁺) and in podocyte progenitors (WT-1⁺/p-ERK⁺ lining Bowman's capsule). These data show that in this model of experimental FSGS, prednisone augments glomerular repair by increasing podocyte number through direct effects on both glomerular epithelial cells. Prednisone limits podocyte loss by reducing apoptosis, and it increases regeneration by augmenting the number of podocyte progenitors. The data support a direct glomerular cell action for prednisone in improving outcomes in FSGS.